I have a 18 year old Husqvarna 225L trimmer that let me down for the first time this spring by not cranking.

I just rebuilt the Walbro WT548 carb, new gas lines, new filter in tank. The H/L screws are in the approximate location as before the rebuild. H was 1 turn, and L was 2 turns.

Installed a new plug that I had in my tool box, but couldn't find my gauge to check the gap.

I test fired it and it ran great. Then I put the air filter in and buttoned everything up and it cuts off after a minute or two of trimming, and is hard to crank back.

Take the filter out and it runs great again. Cleaned the filter with dish soap, even though it didn't appear dirty. Spark arrestor clean.

Put it back together, same deal, cuts off after trimming only a minute or two.

I can't get a new filter until tomorrow, but I suspect that might not cure the problem because my filter looks good, but I can't remember how old it is.

The thing would probably run all day without the filter, but I only ran it about 5 minutes to verify that it would run considerably longer than with the filter.

Any help would be greatly appreciated.